1. Field of the invention
The embodiments of the present invention are directed to a heat pump interoperating hot water feeding apparatus, and more specifically to a heat pump interoperating hot water feeding apparatus that may control the operation of first and second compressors to exhibit the optimal performance by, for each mode, determining whether to activate only a first coolant circulation circuit along which a first coolant is circulated or the first coolant circulation circuit as well as a second coolant circulation circuit along which a second coolant is circulated depending on an external air temperature or target water temperature when the first and second coolants are circulated by first and second compressors, respectively.
2. Description of the Related Art
Generally, heat pumps compress, condense, expand, and evaporate a coolant to heat or cool an indoor space.
Heat pumps may be classified into regular air conditioners each having an indoor unit and an outdoor unit connected to the indoor unit and multi air conditioners each having a plurality of indoor units and an outdoor unit connected to the plurality of indoor units. A heat pump includes a hot water feeding unit for supplying hot water and a room heating unit for heating a room by hot water.
FIG. 1 is a pneumatic circuit diagram illustrating a heat pump interoperation hot water feeding apparatus according to the prior art, wherein the heat pump interoperation hot water feeding apparatus heats water using a dual-source coolant cycle.
Referring to FIG. 1, the conventional heat pump interoperation hot water feeding apparatus includes a first compressor 5 for compressing a first coolant during a room heating mode operation, a first heat exchanger 10 for condensing the first coolant compressed by the first compressor 5, a first expander 15 for expanding the first coolant condensed by the first heat exchanger 10, and a second heat exchanger 20 for evaporating the first coolant expanded by the first expander 15. A flow of the first coolant by the first compressor 5 is referred to as a first coolant circulation unit I.
To implement a dual-source cooling cycle, the conventional heat pump interoperation hot water feeding apparatus includes a second compressor 25 for compressing a second coolant during a room heating mode operation, a third heat exchanger 30 for condensing the second coolant compressed by the second compressor 25, a second expander 35 for expanding the second coolant condensed by the third heat exchanger 30, and a fourth heat exchanger 10 for evaporating the second coolant expanded by the second expander 35. A flow of the second coolant by the second compressor 35 is referred to as a second coolant circulation unit II.
The first heat exchanger 10 and the fourth heat exchanger 10 have the same configuration. During a room heating mode operation, the first cool of the first coolant circulation unit I is condensed and the second coolant of the second coolant circulation unit II is evaporated by the first or fourth heat exchanger 10. As such, a cycle of performing heat exchange on the first and second coolants having different characteristics (or specifications) in a manner of crossing each other to obtain higher performance is called a dual-source cooling cycle, which is well known.
The conventional heat pump interoperation hot water feeding apparatus obtains evaporation latent heat of the second heat exchanger in the first coolant circulation unit by performing heat exchange with external air and obtains condensation latent heat of the third heat exchanger in the second coolant circulation unit from used water that conducts heat exchange with the second coolant while passing through the third heat exchanger.
The conventional heat pump interoperation hot water feeding apparatus has an advantage of being able to obtain a higher-temperature of used water by using a principle of the dual-source cooling cycle. However, the conventional heat pump interoperation hot water feeding apparatus can obtain only the high-temperature used water that is generated after the first and second compressors are operated rather than used water having a temperature desired by a user. Further, the conventional heat pump interoperation hot water feeding apparatus operates the second compressor even when the external air temperature is high or a target water temperature desired by the user is low, thus deteriorating the overall performance of the heat pump interoperation hot water feeding apparatus.